Method of unclogging powder dispenser



July 17, 1962 D. J. BALD! METHOD OF UNCLOGGING POWDER DISPENSER Filed March 15, 1961 //V VEN T01? DEWEY J. BALD! By W Altar/10y nited states This invention relates to the servicing of powder containers, specifically fire extinguishers, adapted to discharge a stream of powder through a nozzle under the pressure of a charge of gas normally confined in a cartridge auxiliary to the extinguisher tank.

A common type of fire extinguisher comprises a tank fitted with a discharge hose and nozzle, having a charge of powder therein and a gas cartridge effective when punctured to pressurize the container and deliver a stream of powder from the nozzle. The powder charge may cake on standing and it is therefore necessary to service the extinguishers periodically to make certain they are always in operative condition. This involves emptying the container, scraping out any caked portion of its contents and then refilling it. The task is thus tedious, time-consuming and wasteful of powder.

I have invented a novel method of performing the servicing of powder-type fire extinguishers or other powder-filled containers which avoids the aforementioned objections. In a preferred practice, I connect a backfiow hose to the cover of the filling opening of the container and a compressed-air hose to the nozzle. By valve manipulation I then cause fiuid pressure to be applied to the powder charge in the container in the reverse of the normal direction. This relieves any clogging of the discharge orifice in the tank and breaks up any caked condition of the powder therein. The backflowing air is conducted to a dust collector where the powder is recovered.

A complete understanding of the invention may be obtained from the following detailed description and ex planation which refer to the accompanying drawing illustrating the present preferred embodiment. In the drawing:

FIGURE 1 is a diagrammatic elevation illustrating the preferred practice;

FIGURE 2 is a plan view of the cover of the dust collector; and

FIGURE 3 is a transverse section through said cover.

Referring now in detail to the drawings, a fire extinguisher tank has a filling opening at one end normally closed by a cover or screw cap generally similar to that shown at 11. A discharge hose '12 is attached to a fitting 13 screwed into a hole adjacent the other end of the tank. A nozzle 14 at the free end of the hose permits a stream of power from tank 10 to be played on a fire. A valve 15 between the hose and nozzle controls the fibw. A gas cartridge 16 on the tank pressurizes it when punctured by a plunger operated by a lever 17. Cover 11 differs from that with which the tank 10 comes equipped in that it is provided with a fitting 18 by which a hose 19 is connected thereto. The other end of the hose is connected to the cover 20 of a dust collector 2 1 by a nipple 20a. Holes 22 in the cover have filter cages 23 thereover permitting the exhaust of air but preventing the loss of air-borne powder.

In performing my method, tank .10 is placed on a bench I B and the conventional cap thereon is removed and replaced by cap 11. Hose 19 is then connected thereto by a coupling 24. A fitting 25 is inserted in nozzle 14 after removal of the conventional tip thereof and a compressedair hose 26 is connected thereto by a coupling 27. Hose 26 is connected to a supply pipe 28 through a valve 29. Valve 29 is then opened and valve 15 is operated to admit backfiowing air through fitting 25 to nozzle 14, hose 12 and tank 10.

The resulting air flow clears any clogging adjacent the orifice into which fitting 13 is screwed and breaks up any caked formation of the powder in the tank. Powder blown back through'hose 19 is separated from the air and gathers in collector 21. It is not necessary, however, to remove the entire powder charge from the tank 10, in order to be assured that the extinguisher is in serviceable condition.

It will be evident that the invention has the advantages of ease, convenience and speed in performing a necessarily i repetitive operation which has heretofore been slow and difficult. formerly lost.

Although I have disclosed herein the preferred embodiing in said cover and separating from the exhaust gas the powder borne thereby.

2. A method of unclogging a powder-dispensing container provided with a filling opening and cover therefor at one end and a discharge hose and nozzle at the other, while comprises admitting compressed gas to said nozzle and hose while exhausting the gas through'an opening in said cover at substantially atmospheric pressure and separating from the exhaust gas the powder borne thereby.

References Cited in the file of this patent UNITED STATES PATENTS 1,039,405 Hubert Sept. 24, 1912 1,908,955 Carmin May 16, 1933 2,309,251 Little Jan. 26, 1943 2,745,418 Balcom May 15, 1956 Edatentecl July 17, 1962' I My method also saves powder which was 

1. A METHOD OF UNCLOGGING A POWDER-DISPENSING CONTAINER PROVIDED WITH A FILLING OPENING AND COVER THEREFOR AT ONE END AND A DISCHARGE HOSE AND NOZZLE AT THE OTHER, WHICH COMPRISES CONNECTING A SOURCE OF COMPRESSED GAS TO SAID NOZZLE, BACKFLOWING GAS FROM THE NOZZLE THROUGH THE HOSE AND CONTAINER AND EXHAUSTING IT THROUGH AN OPENING IN SAID COVER AND SEPARATING FROM THE EXHAUST GAS THE POWDER BORNE THEREBY. 